'Looking Back . . . We Should Have Done Something':
"'Question Mark' was getting to be an aggravation.

The whole thing with the imaginary girlfriend, Jelly, the supermodel he'd say he was making out with in his locked room. The weird faceless picture he posted on Facebook that was supposed to be him.

Andy Koch shared a suite with Virginia Tech gunman Seung Hui Cho and others in 2005. When he heard that Cho had committed the murders, Koch recalled occasional incidents that by themselves had seemed odd but not necessarily threatening at the time. (By Charles Dharapak -- Associated Press)